Wafer processing tape, method of manufacturing wafer processing tape, and method of manufacturing semiconductor device

ABSTRACT

In a wafer processing tape, circular or tongue-shaped notched parts facing the center of an adhesive layer, as seen in a plan view, are formed so as to correspond to a pasting region to a wafer ring to a depth that reaches a release base material from the side of a base material film. Due to the formation of the notched parts, when a peeling force acts on the wafer processing tape, portions of a tacky material layer and the base material film which are more outward than the notched parts are peeled off first, and a portion that is more inward than the notched parts remains on the wafer ring in a protruding state. Accordingly, a peeling strength between the wafer processing tape and the wafer ring can be increased. Methods of manufacturing the tape and a semiconductor device are also provided.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to Provisional Application No.61/446,987 filed on Feb. 25, 2011 by the same Applicant, which is herebyincorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a wafer processing tape used for dicingof a semiconductor wafer and for die bonding of a semiconductor chipobtained by dicing or the like, a method of manufacturing the waferprocessing tape, and a method of manufacturing a semiconductor deviceusing the wafer processing tape.

2. Related Background Art

In recent years, there has been a rapid increase in demands for a widerrange of functions, lighter weight, and smaller sizes in mobile-relateddevices. Accordingly, there has been a stronger need for high-densitypackaging of semiconductor chips. In particular, development has beenfocused on stacked multi-chip packages in which semiconductor chips arelaminated. In some stacked multi-chip packages, semiconductor chips arelaminated and bonded to each other in a die bonding process. Theintroduction of a wafer processing tape that can be used to fix asemiconductor wafer in a dicing process or used concomitantly forbonding a semiconductor chip to a lead frame or the like in a diebonding process is being promoted in manufacturing processes of suchsemiconductor chips (for example, refer to Japanese Patent PublicationNo. 2009-88480).

When fabricating such a wafer processing tape, first, an adhesive filmcomprising an adhesive layer formed on a release base material and adicing film comprising a tacky material layer formed on a base materialfilm are prepared and then pasted together with the adhesive layer andthe tacky material layer facing each other. Next, the base materialfilm, the adhesive layer, and the tacky material layer are pre-cut inaccordance with a wafer shape to obtain a wafer processing tape with adesired shape.

SUMMARY OF THE INVENTION

When processing a semiconductor wafer using such a wafer processingtape, generally, a wafer ring is arranged around the semiconductor waferand the wafer processing tape is pasted to the wafer ring. At thispoint, if the peeling strength between the wafer processing tape and thewafer ring is insufficient, the wafer processing tape peels off from thewafer ring during respective processes such as the dicing process andthe die bonding process, and may adversely affect implementation of theprocesses.

The present invention has been made in order to solve the problemsdescribed above, and an object of the present invention is to provide awafer processing tape capable of increasing a peeling strength with awafer ring, a method of manufacturing the wafer processing tape, and amethod of manufacturing a semiconductor device using the waferprocessing tape.

In order to solve the problems described above, a wafer processing tapeaccording to the present invention is a wafer processing tape to be usedpasted to a wafer ring when processing a semiconductor wafer, the waferprocessing tape comprising: a release base material that constitutes abase of the tape; an adhesive layer provided on one surface of therelease base material so as to correspond to a planar shape of thesemiconductor wafer; a tacky material layer provided so as to cover theadhesive layer; and a base material film provided so as to cover thetacky material layer, wherein regions of the tacky material layer andthe base material film which protrude outward from the adhesive layerserve as a pasting region to the wafer ring, and at least one notchedpart defining a protruding portion facing the center of the adhesivelayer as seen in a plan view is formed in the pasting region to a depththat reaches the release base material from the side of the basematerial film.

With this wafer processing tape, at least one notched part defining aprotruding portion facing the center of the adhesive layer as seen in aplan view is formed so as to correspond to the pasting region to thewafer ring to a depth that reaches the release base material from theside of the base material film. Due to the formation of the notchedpart, when a peeling force acts on the wafer processing tape pasted onthe wafer ring, portions of the tacky material layer and the basematerial film which are more outward than the notched part (outerportions) are peeled off first, and a portion that is more inward thanthe notched part (inner portion) remains on the wafer ring in aprotruding state. As the peeling force further acts, the inner portionis pulled by the outer portions and attempts to peel off. However, dueto an increase in a peeled area and the fact that a point of the pullingaction is positioned further inward from the inner portion, a greaterpeeling force is required to peel off the inner portion. Therefore, withthis wafer processing tape, a peeling strength between the waferprocessing tape and the wafer ring can be increased.

In addition, a plurality of the notched parts are favorably arrangedalong the pasting region. In this case, the peeling strength between thewafer processing tape and the wafer ring can be further increased.

Furthermore, favorably, this wafer processing tape includes at least onenotched part defining a protruding portion that faces away from theoutside of the adhesive layer as seen in a plan view. In this case, aliquid that creates a peeling force such as a cooling water duringdicing can be released from the protruding portions to the outside ofthe wafer processing tape. Therefore, the peeling strength between thewafer processing tape and the wafer ring can be further ensured.

Moreover, favorably, the notched parts do not penetrate the release basematerial. In this case, since the notched parts are prevented fromacting when peeling off the release base material during the use of thewafer processing tape, the release base material can readily be peeledoff.

In addition, favorably, if a denotes a thickness of the release basematerial and d denotes a depth of the notched parts, then 0<d/a≦0.7 issatisfied. By satisfying this condition, an effect of the notched partscan be sufficiently exerted.

Furthermore, a method of manufacturing a wafer processing tape accordingto the present invention is a method of manufacturing a wafer processingtape that is used pasted to a wafer ring when processing a semiconductorwafer, the method comprising: providing an adhesive film formed of arelease base material that constitutes a base of the tape and anadhesive layer provided on one surface of the release base material soas to correspond to a planar shape of the semiconductor wafer; providinga tacky film comprising a base material film and a tacky material layerprovided on one surface of the base material film; pasting the adhesivefilm and the tacky film such that the adhesive layer and the tackymaterial layer face each other; and forming at least one notched partdefining a protruding portion facing the center of the adhesive layer asseen in a plan view, the at least one notched part being formed in apasting region of the tacky film that protrudes outward from theadhesive layer and is configured for pasting to the wafer ring, the atleast one notched part further being formed, to a depth that reaches therelease base material from the side of the base material film.

With a wafer processing tape obtained by this manufacturing method, atleast one notched part defining a protruding portion facing the centerof the adhesive layer as seen in a plan view is formed so as tocorrespond to the pasting region to the wafer ring to a depth thatreaches the release base material from the side of the base materialfilm. Due to the formation of the notched part, when a peeling forceacts on the wafer processing tape pasted on the wafer ring, portions ofthe tacky material layer and the base material film which are moreoutward than the notched part (outer portions) are peeled off first, anda portion that is more inward than the notched part (inner portion)remains on the wafer ring in a protruding state. As the peeling forcefurther acts, the inner portion is pulled by the outer portions andattempts to peel off. However, due to an increase in a peeled area andthe fact that a point of the pulling action is positioned further inwardfrom the inner portion, a greater peeling force is required to peel offthe inner portion. Therefore, with this wafer processing tape, a peelingstrength between the wafer processing tape and the wafer ring can beincreased.

In addition, a plurality of the notched parts are favorably formedwithin the pasting region. In this case, the peeling strength betweenthe wafer processing tape and the wafer ring can be further increased.

Furthermore, the method of manufacturing a wafer processing tapeaccording to the present invention is favorably further comprisingforming at least one notched part defining a protruding portions thatfaces away from the outside of the adhesive layer as seen in a planview. In this case, a liquid that creates a peeling force such as acooling water during dicing can be released from the protruding portionsto the outside of the wafer processing tape. Therefore, the peelingstrength between the wafer processing tape and the wafer ring can befurther ensured.

In addition, the notched parts are favorably formed so as not topenetrate the release base material. In this case, since the notchedparts are prevented from acting when peeling off the release basematerial during the use of the wafer processing tape, the release basematerial can readily be peeled off.

Furthermore, the notched parts are favorably formed such that if adenotes a thickness of the release base material and d denotes a depthof the notched parts, then 0<d/a≦0.7 is satisfied. By satisfying thiscondition, an effect of the notched parts can be sufficiently exerted.

Moreover, a method of manufacturing a semiconductor device according tothe present invention is a method of manufacturing a semiconductordevice using the wafer processing tape described above, the methodcomprising: fixing a film laminate obtained by peeling off the releasebase material from the wafer processing tape to one surface of asemiconductor wafer via the adhesive layer; fixing the wafer ring to thepasting region via the tacky material layer in the pasting region of thefilm laminate; and dicing the semiconductor wafer while supplyingcooling water to a dicing blade.

According to this method of manufacturing a semiconductor device, sincea peeling strength between the wafer processing tape and the wafer ringcan be sufficiently ensured, the wafer processing tape can be suppressedfrom becoming peeled off from the wafer ring during processes.Therefore, workability can be improved and a fabrication yield of thesemiconductor device can be ensured.

According to the present invention, a peeling strength with a wafer ringcan be improved. In addition, a fabrication yield of the semiconductordevice can be ensured.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view showing an embodiment of a wafer processing tapeaccording to the present invention;

FIG. 2 is a cross-sectional view taken along II-II in FIG. 1;

FIG. 3 is a diagram showing a method of mounting the wafer processingtape to a wafer ring;

FIG. 4 is a diagram showing a mounted state of the wafer processing tapeto a wafer ring;

FIG. 5 is a diagram showing a dicing process of a semiconductor wafer;

FIG. 6 is a perspective view showing an effect of notched parts;

FIG. 7 is a plan view of a wafer processing tape according to amodification;

FIG. 8 is a plan view of a wafer processing tape according to anothermodification;

FIG. 9 is a plan view of a wafer processing tape according to yetanother modification;

FIG. 10 is a plan view of a wafer processing tape according to yetanother modification;

FIG. 11 is a plan view of a wafer processing tape according to yetanother modification;

FIG. 12 is a plan view of a wafer processing tape according to yetanother modification;

FIG. 13 is a plan view of a wafer processing tape according to yetanother modification;

FIG. 14 is a plan view of a wafer processing tape according to yetanother modification;

FIG. 15 is a plan view of a wafer processing tape according to yetanother modification; and

FIG. 16 is a plan view of a wafer processing tape according to yetanother modification.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, preferred embodiments of a wafer processing tape, a methodof manufacturing the wafer processing tape, and a method ofmanufacturing a semiconductor device using the wafer processing tapeaccording to the present invention will be described in detail withreference to the drawings.

[Configuration of Wafer Processing Tape]

FIG. 1 is a plan view showing an embodiment of a wafer processing tapeaccording to the present invention. In addition, FIG. 2 is across-sectional view taken along II-II in FIG. 1. A wafer processingtape 1 in FIGS. 1 and 2 is a long tape used for dicing of asemiconductor wafer and for die bonding of a semiconductor chip obtainedby dicing, and is normally wound into a roll.

As shown in FIGS. 1 and 2, the wafer processing tape 1 has been precutand comprises: a release base material 2 that constitutes a base of thetape; an adhesive layer 3 circularly provided at regular intervals onone surface of the release base material 2 so as to correspond to theshape of a semiconductor wafer; a tacky material layer 4 circularlyprovided so as to cover the adhesive layer 3; and a base material film 5provided in the same shape as the tacky material layer 4 so as to coverthe tacky material layer 4. Embankments 6 arranged at regular intervalsfrom the circular tacky material layer 4 and the base material film 5are provided at both edges in a width-direction of the release basematerial 2. The embankments 6 are formed during pre-cutting of the tackymaterial layer 4 and the base material film 5. Moreover, the releasebase material 2 and the adhesive layer 3 are formed by an adhesive film18 to be described later, and the base material film 5 and the tackymaterial layer 4 are formed by a tacky film 17 to be described later.

Among ends of the tacky material layer 4 and the base material film 5,regions protruding outward than the adhesive layer 3 constitute apasting region P to the wafer ring. A plurality of notched parts 11formed with a depth that reaches the release base material 2 from theside of the base material film 5 is arranged in an annular pattern inthe pasting region P. As illustrated in FIG. 1, the notched parts 11have a circular or tongue-like shape as seen in a plan view, and areformed oriented such that protrusions of the notched parts 11 are on acenter side of the adhesive layer 3. The depths of the notched parts 11are favorably set such that if a denotes a thickness of the release basematerial 2 and d denotes the depth of the notched parts, then 0<d/a≦0.7is satisfied and, at the same time, the release base material 2 is notpenetrated. Moreover, while the number of notched parts 11 to bearranged is not particularly limited, for example, the notched parts 11are favorably arranged at intervals of 2 to 3 degrees.

[Fabrication of Semiconductor Device]

When manufacturing a semiconductor device using the wafer processingtape 1 described above, first, as shown in (a) of FIG. 3, the releasebase material 2 is peeled off from the wafer processing tape 1 to obtaina film laminate 12. Next, as shown in (b) of FIG. 3, the film laminate12 is fixed to one surface of a semiconductor wafer 13 via the adhesivelayer 3 exposed by the peeling of the release base material 2. Inaddition, as shown in (b) of FIG. 3 and in FIG. 4, a wafer ring 14 isfixed via the tacky material layer 4 in a pasting region P of the filmlaminate 12.

Next, as shown in FIG. 5, dicing of the semiconductor wafer 13 and theadhesive layer 3 is performed while supplying cooling water 16 to adicing blade 15. After dicing, the tacky material layer 4 is irradiatedwith high-energy rays to reduce a tack strength, and a semiconductorchip with the adhesive layer 3 is picked up from the base material film5. Subsequently, by attaching the semiconductor chip to a predeterminedsupporting member via the adhesive layer 3, a semiconductor device isobtained.

When performing the dicing described above, the wafer processing tape 1(film laminate 12) is subjected to pressure from the cooling water 16.Therefore, when the peeling strength between the wafer processing tape 1and the wafer ring 14 is insufficient, the wafer processing tape 1 maypeel off from the wafer ring 14 and may adversely affect dicing.

In contrast, with the wafer processing tape 1, as shown in FIG. 1,circular or tongue-shaped notched parts 11 facing the center of theadhesive layer 3 as seen in a plan view are formed so as to correspondto the pasting region P to the wafer ring 14 to a depth that reaches therelease base material 2 from the side of the base material film 5. Dueto the formation of the notched parts 11, when a peeling force acts onthe wafer processing tape 1 pasted on the wafer ring 14, as shown inFIG. 6, portions of the tacky material layer 4 and the base materialfilm 5 which are more outward than the notched part 11 (outer portions17 a) are peeled off first, and a portion that is more inward than thenotched parts 11 (inner portion or flap 17 b) remains on the wafer ring14 in a protruding state.

As the peeling force further acts, the inner portion 17 b is pulled bythe outer portions 17 a and attempts to peel off. However, due to anincrease in a peeled area and the fact that a point of the pullingaction is positioned further inward than the inner portion 17 b, agreater peeling force is required to peel off the inner portion 17 b.Therefore, with this wafer processing tape 1, the peeling strengthbetween the wafer processing tape 1 and the wafer ring 14 can beincreased and the wafer processing tape 1 can be suppressed frombecoming peeled off from the wafer ring 14 during processes. Thiscontributes toward improving workability, and an improvement of afabrication yield of the semiconductor device can be achieved. Moreover,the tacky film 17 is not limited to an ultraviolet-curable film and apressure-sensitive film can also be used. Since peeling from the waferring 14 is more likely to occur with a pressure-sensitive film, theformation of the notched parts 11 described above is particularlyuseful.

In addition, with the wafer processing tape 1, the depths of the notchedparts 11 are set such that if a denotes a thickness of the release basematerial 2 and d denotes the depth of the notched parts, then 0<d/a≦0.7is satisfied and, at the same time, the release base material 2 is notpenetrated. Accordingly, an effect of the notched parts 11 can besufficiently exerted. In addition, since the notched parts 11 areprevented from acting when peeling off the release base material 2during the use of the wafer processing tape 1, the release base material2 can readily be peeled off.

[Fabrication of Wafer Processing Tape]

To fabricate the wafer processing tape 1, for example, SD-3004manufactured by Hitachi Chemical Co., Ltd. is prepared as the tacky film17 constituted by the tacky material layer 4 and the base material film5. In addition, for example, the HS-270 series manufactured by HitachiChemical Co., Ltd. is prepared as the adhesive film 18 constituted bythe adhesive layer 3 and the release base material 2. Next, circularpre-cutting to a diameter of 320 mm of the adhesive film 18 is performedso that a notching depth to the release base material 2 is equal to orless than 20 um in order to remove unnecessary portions of the adhesivelayer 3. Subsequently, the tacky material layer 4 and the adhesive layer3 are arranged so as to face each other to paste together the adhesivefilm 18 and the tacky film 17 at conditions of room temperature, alinear pressure of 1 kg/cm, and a speed of 0.5 m/minute. Next, circularpre-cutting to a diameter of 390 mm of the tacky film 17 is performedconcentrically with the adhesive layer 3 so that a notching depth to therelease base material 2 is equal to or less than 20 um in order toremove unnecessary portions of the tacky material layer 4 and the basematerial film 5 and to form the embankments 6. After pre-cutting thetacky film 17, using a predetermined die, circular or tongue-shapednotched parts 11 are formed arranged in an annular pattern at positionsapproximately 5 mm inward from an edge of the tacky film 17 to obtainthe wafer processing tape 1.

[Evaluation of Peeling Strength]

A wafer processing tape (comparative example) on which the notched parts11 are not formed was fabricated separate to the wafer processing tape 1(example) obtained by the manufacturing method described above.Subsequently, a first test specimen was fabricated by cutting off arectangular region having a width of 10 mm and a length of 50 mm andincluding one notched part 11 from the example tape, and after peelingoff the release base material 2, laminating the tacky material layer 4washed by ethanol and the base material film 5 onto a surface of anadherend (SUS 304) at room temperature. In addition, a second testspecimen was fabricated by cutting off a region similar to therectangular region described above from the comparative example tape,and after peeling off the release base material 2, laminating the tackymaterial layer 4 washed by ethanol and the base material film 5 onto asurface of an adherend (SUS 304) at room temperature.

Measurements of 90-degree peeling strengths performed on the first testspecimen and the second test specimen revealed that while a peelingstrength of the tacky material layer 4 and the base material film 5 withrespect to the adherend had an maximum value of 40 N/m in the first testspecimen, a peeling strength of the tacky material layer 4 and the basematerial film 5 with respect to the adherend had a maximum value of 10N/m in the second test specimen. From this result, it was confirmed thatthe formation of the notched parts 11 in the pasting region Pcontributes toward increasing the peeling strength of the waferprocessing tape 1.

[Modifications]

The present invention is not limited to the embodiment described above.For example, while the embankments 6 are formed by a circularpre-cutting process of the tacky film 17 in the embodiment describedabove, as shown in FIG. 7, a wafer processing tape 21 on which theembankments 6 are not formed may be adopted instead.

In addition, the notched parts need only be shaped so as to protrudetoward the center of the adhesive layer 3 as seen in a plan view. Assuch, various modifications can be applied. For example, rectangularnotched parts 32 may be formed as with a wafer processing tape 31 shownin FIG. 8, or notched parts 42 having approximate V-shapes may be formedas with a wafer processing tape 41 shown in FIG. 9.

Furthermore, for example, circular or tongue-shaped notched parts 52 maybe doubly formed as with a wafer processing tape 51 shown in FIG. 10,circular or tongue-shaped notched parts 62 may be formed staggered alongtwo annular lines as with a wafer processing tape 61 shown in FIG. 11,or positions of notched parts 72 from the tacky material layer 4 and thebase material film 5 may be set random for each notched part 72 as witha wafer processing tape 71 shown in FIG. 12.

In addition, as with a wafer processing tape 81 shown in FIG. 13,notched parts 11 may be respectively formed only on one of the edges ofthe tacky material layer 4 and the base material film 5. Accordingly,when using the wafer processing tape 81, the release base material 2 canbe easily peeled off from the side of the region in which the notchedparts 11 are formed. Moreover, when using the wafer processing tape 81,cooling water 16 during dicing is favorably directed toward the regionin which the notched parts 11 are formed.

On the other hand, in addition to a protruding portion that faces thecenter of the adhesive layer 3 as seen in a plan view, a protrudingportion that faces the outside of the adhesive layer 3 as seen in a planview may be further formed on a notched part. For example, as with awafer processing tape 91 shown in FIG. 14, a protruding portion 92 afacing the center of the adhesive layer 3 and a protruding portion 92 bfacing the outside of the adhesive layer 3 may be arranged side by sidein a circumferential direction of the adhesive layer 3 to form anapproximately N-shaped notched part 92. In addition, according to asimilar concept, an approximately S-shaped notched part 102 may beformed by a protruding portion 102 a facing the center of the adhesivelayer 3 and a protruding portion 102 b facing the outside of theadhesive layer 3 as with a wafer processing tape 101 shown in FIG. 15.Furthermore, as with a wafer processing tape 111 shown in FIG. 16, aprotruding portion 112 a facing the center of the adhesive layer 3 and aprotruding portion 112 b facing the outside of the adhesive layer 3 maybe arranged side by side in a radial direction of the adhesive layer 3to form an approximately X-shaped notched part 112.

With such wafer processing tapes 91, 101, and 111, while inner portionsof the notched parts 92, 102, and 112 remain on the wafer ring 14 in aprotruding state at the protruding portions 92 a, 102 a, and 112 a thatface the center of the adhesive layer 3, inner portions of the notchedparts 92, 102, and 112 are turned up at the protruding portions 92 b,102 b, and 112 b that face the outside of the adhesive layer 3, andcooling water 16 during dicing can be released to the outside of thewafer processing tapes 91, 101, and 111 from these portions. Therefore,the peeling strengths between the wafer processing tapes 91, 101, and111 and the wafer ring 14 can be further ensured.

What is claimed is:
 1. A wafer processing tape having a pasting region to be pasted to a wafer ring used when processing a semiconductor wafer, the wafer processing tape comprising: a release base material constituting a base of the tape; an adhesive layer provided on one surface of the release base material so as to correspond to a planar shape of the semiconductor wafer; a tacky material layer provided so as to cover the adhesive layer; and a base material film provided so as to cover the tacky material layer, wherein: in a plan view, regions of the tacky material layer and the base material film protruding outward from the adhesive layer serve as the pasting region to the wafer ring, in the plan view, at least one notched part is formed entirely outside the adhesive layer, in the base material film and the tacky material layer in the pasting region, to a depth reaching the release base material from the side of the base material film, the notched part being spaced inwardly from an outer perimeter of the pasting region, and in the plan view, a part of the tacky material layer and the base material film in the pasting region is partitioned by the notched part into: (a) a first portion nearer than the notched part to the center of the adhesive layer, and (b) a second portion more distant than the notched part from the center of the adhesive layer but continuous with the first portion around the notched part, and having a flap bounded by the notched part so as to be embraced by the notched part and to protrude toward the center of the adhesive layer.
 2. The wafer processing tape according to claim 1, wherein a plurality of said notched parts are arranged discontinuously from each other along the pasting region so as to define a plurality of said flaps.
 3. The wafer processing tape according to claim 1, including at least one additional notched part formed entirely outside the adhesive layer and defining a flap that faces away from the outside of the adhesive layer, as seen in the plan view.
 4. The wafer processing tape according to claim 1, wherein the at least one notched part does not penetrate the release base material.
 5. The wafer processing tape according to claim 1, wherein the at least one notched part extends partially through the thickness of the release base material.
 6. A wafer processing tape having a pasting region to be pasted to a wafer ring used when processing a semiconductor wafer, the wafer processing tape comprising: a release base material constituting a base of the tape; an adhesive layer provided on one surface of the release base material so as to correspond to a planar shape of the semiconductor wafer; a tacky material layer provided so as to cover the adhesive layer; and a base material film provided so as to cover the tacky material layer, wherein: in a plan view, regions of the tacky material layer and the base material film protruding outward from the adhesive layer serve as a pasting region to the wafer ring, in the plan view, the pasting region includes a flap formed entirely outside the adhesive layer, spaced inwardly from an outer perimeter of the pasting region, defined by a notch part spaced inwardly from an outer perimeter of the pasting region, the flap and protruding toward a center of the adhesive layer, and the flap extends to a depth reaching the release base material from the side of the base material film. 